# NCERT Class 11 Physics very short Questions & Answers

NCERT Class 11 Physics very short Questions & Answers NCERT Class 11 Physics QUESTIONS

# NCERT Class 11 Physics very short Questions & Answers

31 The material suitable for making electromagnets should have
A high retentivity and high coercivity.
B low retentivity and low coercivity.
C high retentivity and low coercivity.
D low retentivity and high coercivity.

Answer: high retentivity and low coercivity.
32 Curie temperature is the temperature above which
A a ferromagnetic material becomes paramagnetic.
B a ferromagnetic material becomes diamagnetic.
C a paramagnetic material becomes diamagnetic.
D a paramagnetic material becomes ferromagnetic.

Answer: a ferromagnetic material becomes paramagnetic.
33 Three needles N1 N2 and N3 are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet, when brought close to them, will
A attract N1 strongly, but repel N2 and N3 weakly.
B attract all three of them.
C attract N1 and N2 strongly but repel N3.
D attract N1 strongly, N2 weakly and repel N3 weakly.

Answer: attract N1 strongly, N2 weakly and repel N3 weakly.
34 Which of the following options are correct? If a conductor has a potential V 4- 0 and there are no charges anywhere else outside, then
A there must not be charges on the surface or inside itself.
B there cannot be any charge in the body of the conductor.
C there must be charges only on the surface.
D there must be charges inside the surface.

Answer: there cannot be any charge in the body of the conductor.
35 Which of the following options is correct? In a region of constant potential
A the electric field is zero.
B there can be charge inside the regiofi.
C the electric field is uniform.
D the electric field shall necessarily change if a charge is placed outside the region.

Answer: the electric field is zero.
36 64 drops each having the capacity C and potential V are combined to form a big drop. If the charge on the small drop is q, then the charge on the big drop will be
A 64q
B 16q
C 2q
D 4q

37 The radii of two metallic spheres A and B are r1 and r2 respectively (r1 > r2). They are connected by a thin wire and the system is given a certain charge. The charge will be greater
A on the surface of the sphere A.
B on the surface of the sphere B.
C equal on both.
D zero on both.

Answer: on the surface of the sphere A.
38 A magnetic needle is kept in a non-uniform magnetic field. It experiences
A a torque but not a force.
B neither a force nor a torque.
C a force and a torque.
D a force but not a torque.

Answer: a force and a torque.
39 Let the magnetic field on earth be modelled by that of a point magnetic dipole at the centre of earth. The angle of dip at a point on the geographical equator
A is always zero.
B can be zero at specific points.
C cannot be positive or negative.
D is not bounded.

Answer: can be zero at specific points.
40 A strong magnetic field is applied on a stationary electron. Then the electron
A moves in the direction of the field.
B remained stationary.
C moves perpendicular to the direction of the field.
D moves opposite to the direction of the field.